Gran Rey Cero

This is a story set in an AU where during Ichigo's final battle with Ulquiorra while he is in the vasto lord form, he foolishly rips off his mask in such a way that he becomes an arrancar and as such he becomes a full hollow permanently, this also creates a storm of reiatsu killing Inoue and hollowifiying her, but heals Nel's mask, he becomes the king of hueco mundo, Gran Rey Cero.